MXPA03010160A

MXPA03010160A - Method and apparatus for concatenated convolutional encoding and interleaving.

Info

Publication number: MXPA03010160A
Application number: MXPA03010160A
Authority: MX
Inventors: Marko Paul
Original assignee: Xm Satellite Radio Inc
Priority date: 2001-05-07
Filing date: 2002-05-07
Publication date: 2005-03-07
Also published as: EP1397868A4; CA2446395A1; EP1397868B1; ES2310605T3; CA2446395C; US20130073929A1; WO2002091594A1; US20060280206A1; EP1397868A1; JP4017987B2; US7058086B2; DE60228443D1; US7653088B2; US20020003813A1; ATE405993T1; US8290000B2; US20100169749A1; US8667344B2; JP2004527964A

Abstract

A method and apparatus for convolutionally encoding (30) and interleaving (46, 48) a source data stream for transmission on one or more transmission channels (66, 68). Convolutionally encoded data groups (36) are time-interleaved (46) to disperse selected bits of puncture groups (45) in the data groups, bits in between data groups, and bits in selected sets of data groups, facilitating reconstruction of the source data from at least a portion of the interleaved data received on at least one transmission channel. The time-interleaving functions (46) are selected to facilitate reconstruction of the source data from one transmission channel following continuous blockage. Puncture groups are selected to allow reconstruction of the source data using a minimum number of puncture group bits. Multiple combinations (44a-44d) of puncture group bits can be used to reconstruct the source data following blockage of one channel. A Viterbi decoder (26) performs decoding.

Description

METHOD AND APPARATUS FOR CODING AND INTERCALING IN SPIRAL. CONCATENATED This application is a continuation of U.S. Patent Application Serial No. 09 / 433,861, filed November 4, 1999, which is a partial continuation of U.S. Patent Application No. of Series 09 / 318,938, filed May 26, 1999. Now issued as U.S. Patent No. 6,154,452.

FIELD OF THE INVENTION The invention relates to a method and apparatus for encoding spiral interleaved, concatenated, of a source data stream for transmission.

Background of the Invention Radio frequency transmissions are often subject to the weakening of multiple trajectories. Signal blockages as receivers may occur due to physical obstructions between the transmitter and the receiver or service interruptions. For example, mobile receivers encounter physical obstructions when they pass through tunnels or travel near buildings or trees, which prevent the reception of the line of sight ("LOS") signal. Service interruptions may occur, on the other hand, when the noise or cancellations of reflections of multipath signals are sufficiently high, with respect to the desired signal of the program material in a transmission channel for a selected time interval, with respect to the transmission of the same program material in a second transmission channel. The duration of the time interval is determined by the duration of the interruption of service to be avoided. The non-delayed channel is delayed in the receiver, so the two channels can be combined, or the program material in the two selected channels, by means of the receiver's circuitry. One such time diversity system is a digital broadcasting system ("DAS"), which employs two satellite transmission channels. The interleaving of data symbols in the transmission channels of a time diversity system can be used to mitigate, in particular, the effects of a deep and slow weakening. An interleaver rearranges a set of coded, consecutive data symbols in a data stream to be transmitted, such that the symbols in the set extended by a duration of time greater than the duration of a deep and slow weakening. A receiver, which has a deinterleaver, rearranges the received symbols to their original order. The interleaved data symbols, which are deinterleaved, however, undergo independent weakening, which may not be migrated by the interleaver, due to size restrictions of the interleaver. In addition, a DBS generally has a requirement for protection against a selected minimum duration interrupt, when both satellite channels are available. Thus, there is a need for a communication system that provides such interrupt protection. In addition, there is a need for a communication system that provides maximum protection of interruptions, within the reasonable memory and delay restrictions of the interleaver, when only a single transmission channel is available.

SUMMARY OF THE INVENTION The disadvantages described above are overcome and a number of advantages are realized with the method and apparatus provided by the present invention, for coding a stream of source data by spiral coding. One or more coded data streams are interleaved and transmitted in one or more transmission channels. The data groups generated by means of spiral encoding are interleaved, according to a plurality of time interleaving functions, to scatter selected bits within drill groups of the data groups, to scatter bits between groups of data. data, as well as scattering bits in selected sets of data groups, and thus facilitate the reconstruction of the source data stream from at least a portion of the data stream interleaved in at least one transmission channel. In accordance with another aspect of the present invention, two or more transmission channels are employed. The time interleaving functions are selected to facilitate the reconstruction of the source data stream from at least a portion of the interleaved data stream, received in at least one of the transmission channels, followed by the continuous blocking of the data streams. transmission channels. According to yet another aspect of the present invention, a single transmission channel is employed. The time interleaving functions are selected to facilitate the reconstruction of the source data stream from at least a portion of the interleaved data stream received in the transmission channel, followed by a continuous blockage of the transmission channel. According to yet another aspect of the present invention, each of the drill groups comprises subsets of bits in the data groups. These subsets of bits are selected so that only a minimum number of subsets is required to reconstruct the data stream source from more than one of the transmission channels. According to another aspect of the present invention, the subsets of bits are selected so that multiple combinations of the subsets can be received in both of the interleaved transmission channels and allow reconstruction of the source data stream thereof, following the blocking of one of the transmission channels. According to another aspect of the present invention, the decoding in the receiver is performed using spiral decoding. The decoding is preferably carried out using a Viterbi decoder. In accordance with another aspect of the present invention, the time interleaving functions are selected to optimize error correction during Viterbi decoding. According to another aspect of the present invention, the coded signals are interleaved and then demulti-channelized for multi-channel transmission. According to another aspect of the present invention, the coded signals are demulti-channelized and interleaved before transmission. According to one embodiment of the present invention, there is provided a method of interleaving a data stream source for transmission, comprising the steps of: (1) encoding a data stream source to generate a data stream output , which uses a spiral coding scheme, which has a selected code regime, this data stream output is characterized as a series of data sets, each of the data sets comprising a plurality of data sets Perforated, each of these groups of punched data has a reduced code rate with respect to the regime of the selected code; (2) interleaving the data groups, according to a plurality of interleaving functions, to scatter the bits in the data groups, within the output data stream and generate an interleaved data stream, and (3) transmit the interleaved data stream for the transmission of a transmission channel, the interleaving functions in time being selected to scatter different groups of bits in the output data stream from the group consisting of bits in one of the data groups perforated, in groups of adjacent data, and bits in the selected sets of the data groups, to facilitate the reconstruction of the source data stream from at least a portion of the interleaved data stream, received in at least one of the transmission channels. The time interleaving functions are selected, in accordance with the present invention, to facilitate the reconstruction of the source data stream from at least a portion of the interleaved data stream. The groups of punched data each comprise subsets of bits in the data groups. The subsets of bits are selected in accordance with the present invention, so that only a minimum number of the subsets is required to reconstruct the source data stream from the transmission channel. The subsets of bits are also selected so that multiple combinations of the subsets can be received in at least two interspersed transmission channels and allow the reconstruction of the source data stream thereof, following the blocking of one of the transmission channels. transmission. The interleaved data stream is decoded using the selected code rate, according to the present invention. The decoding is preferably performed using spiral decoding, such as by means of a Viterbi decoder. The time interleaving functions are selected in accordance with the present invention, to optimize error correction, during Viterbi decoding.

BRIEF DESCRIPTION OF THE DRAWINGS The various aspects, advantages and novel features of the present invention will be more readily understood from the following detailed description, when read in conjunction with the accompanying drawings, in which: Figure 1 is a block diagram of a communication system using interleaving according to an embodiment of the present invention; Figure 2 is a block diagram, illustrating the coding and interleaving device, and the data stream generated by an encoder, according to an embodiment of the present invention; Figure 3 illustrates a spiral encoder and the output data stream, according to one embodiment of the present invention; Figures 4A, 4B, 4C, 4D, 4E, 4F and 4G illustrate groups of punched data, according to one embodiment of the present invention; Figure 5 is a block diagram, illustrating a coding and interleaving device, and the data stream generated by an encoder, according to an embodiment of the present invention; Figure 6 illustrates the interleaving functions in time, according to one embodiment of the present invention; Figure 7 illustrates the exemplary interleaving of sets and subsets of punctured data groups, according to one embodiment of the present invention; Figure 8 is a block diagram of a receiver employing decoding and de-interleaving, according to an embodiment of the present invention; and Figure 9 illustrates an exemplary digital broadcast system for transmitting satellite and terrestrial signals.

Through the figures of the drawing, similar reference numbers will be understood to refer to similar parts and components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 illustrates a communication system 10, which employs a variety of combinations. Therefore, a plurality of transmission channels are used to transmit the same data source or program material. In the illustrated example, two transmission channels are used. A method and apparatus will be described for illustrative purposes in relation to a DBS employing two satellites, according to one embodiment of the present invention. A receiver on a fixed or mobile platform receives two or more signals transmitted through different channels and selects the strongest signals or combines the signals. These signals can be transmitted in the same radiofrequency, using resistant modulation or interference to multiple trajectories, or at different radiofrequencies, with or without modulation resistant to multiple trajectories. In any case, the attenuation due to physical obstructions is minimized because the obstructions are rarely in the two of both satellites. However, it will be understood that more than two transmission channels may be used and that these transmission channels may be of any type related to the data communication path per wireline or wireless. With continued reference to Figure 1, a stream of source data is encoded using a forward error correction algorithm (FEC) with a selected code rate, as indicated at 12, to allow the loss of a bit percentage of channel during transmission, while maintaining error-free output. The output of the FEC encoder 12 is interleaved by means of the interleaver 14, randomly in the order of bits, and to de-correlate bit errors caused by blocking and propagation of multiple paths. The interleaving of the present invention, which is described below in relation to FIGS. 6 and 7, allows a continuous blocking of a selected duration (for example of approximately 4 seconds) when both transmission channels are available. In addition, the coded data stream is drilled to create perforated groups for the respective transmission channels. The drill groups are selected so that only a minimum number of bit sub-bits in the drilled data groups are required to reconstruct the source of the data stream from more than one of the transmission channels. further, the drilling groups are selected so that multiple combinations of subsets can be received in both transmission channels and allow reconstruction of the source data stream, following the blocking of one of the transmission channels. The drilling groups, the subsets of bits in the drilling groups and the multiple combinations of subsets are described below in relation to Figures 4A to 4G. As shown in Figure 1, the coded and interleaved bits are demulticalised by means of the demultiplexer 16, in respective data streams, for transmission in respective channels 18 and 20. As described below in relation to Figure 5, the data encoded can be demulting before the interleaving. In the illustrated example, the source data stream is subjected to external FEC coding (eg, Reed-Salomon (255, 223) encoding and interleaving blocks) before the spiral encoding, with the element encoding and intercalating of the present invention. The coded and interleaved data streams are provided with synchronization data to allow the synchronization and alignment of the data signals in the receiver, before multicasting, deinterleaving and decoding, as indicated in 22, 24 and 26 in Figure 1 and it is described below in relation to Figure 8. As shown in Figure 2, the bit stream source is encoded using a spiral encoder, in accordance with the present invention. As previously noted, the source data stream may be the protected bitstream of Reed-Salomon (RS). Spiral encoder 30 is preferably a 1/3 rate grooved encoder with a restricted length of 7. Thus, for each input bit from the source data stream, a 3-bit symbol is generated, as indicated through output 32 of the encoder. A data group 34, generated by the spiral encoder 30, is illustrated in FIG. 3. In accordance with the present invention, each group 34 of data generated by the spiral encoder is subjected to 1 in 9 perforations. A group 36 of punched data is illustrated in Figure 4A. The bit positions of the data group are numbered from 1 to 9 for illustrative purposes. The fifth bit position is preferably perforated. The remaining eight bit positions are divided between two transmission channels, 18 and 20 (for example, two satellite channels). For example, the data at the bit positions 1, 2, 3 and 4 are preferably transmitted on a satellite channel 18, and the data at the bit positions 6, 7, 8 and 9 are preferably transmitted on the other channel 20. of satellite, as illustrated by satellite 1 only drilling pattern 38 and satellite 2 only of drilling pattern 40, in Figure 4B and 4C, respectively, The bit positions of the data group for a transmission channel are hereinafter generally referred to as channel data groups 45. Thus, the scheme for the data stream to be transmitted immediately after the spiral coding and the perforation is R = 3/8. Each of the two transmission channels in the illustrated mode, therefore, effectively transmits at a rate R = 174. This is advantageous because the transmitted data stream can still be decoded even when only one of the channels 18 or 20 is available to a receiver.

The interleaving operations of the present invention will now be described with continued reference to FIG. 2. Two sets of punched, exemplary data, 36a and 36b are shown to illustrate the six-bit spiral encoding from the source data stream 42. As indicated in 32, these bits are generated for each of the six bits and are numbered, Ib, 1c, 2a, 2b, 2c, ... 6a, 6v, 6c. Bits 2b and 5b are punched according to 1 in 9 perforations, previously described. In the presence of damaged channel conditions, where the bits of one or both channels may be lost, the groups 36 of punched data used, according to the present invention, are advantageous, because they present multiple combinations of data bits. perforated (hereinafter referred to as the subsets of the bits 4) that allow the reconstruction of the source data stream from more than one of the transmission channels, using a minimum number of the subsets. For example, with reference to Figure 4D, the source data stream 42 can be reconstructed from the combination of the subcontact 44a, which comprises the data at the bit positions 1 and 2 of a transmission channel with the subset 44b, which comprises the data in the bit positions 6 and 7 of the other transmission channel. Similarly, with reference to Figure 4E, the source of the data stream 42 can be reconstructed from the combination of the subset 44c, which comprises the data at the bit positions 3 and 4 of a transmission channel with the subset 44d, which it comprises the data at bit positions 8 and 9 of the other transmission channel. Other combinations of subsets, as shown in Figures 4D and 4G, provide the same results. As described below in relation to the memory array 92 in Figure 8, the bits of the satellite channels 18 and 20 are aligned and stored in the respective memory elements. For example, bits 2 and 6, 2 and 7, 3, 8, 4 and 9 of the two channel data groups 45, illustrated in Figures 4B and 4C are aligned and stored with respect to each other. The combination shown in Figures 4F and 4G illustrates the manner in which the source data stream 42 can be reconstructed from the combination of bits from different memory elements. As shown in Figure 4F, bits 1 and 2 can be combined with bits 8 and 9, to reconstruct the source data stream. Similary, bits 3 and 4 can be combined with bits 6 and 7, to reconstruct the source data stream, as shown in Figure 4C.

The correction of errors in a receiver is preferably performed using the Viterbi decoding. When a QPSK symbol transmitted on a channel is received in error in the illustrated example, there is an opportunity that both bits are in error following the spiral encoding, at the rate of R = 1/3. To improve the probability that the Viterbi decoder corrects a received symbol in error, the bits of the symbol are interleaved so that they still pass through the Viterbi decoder at intervals greater than the constriction length. In accordance with the present invention, an interleaver 46 (FIG. 2) preferably employs a number of time interleaving functions to disperse bits in groups 36 of punched data, to disperse data groups 34 and to disperse sets of data groups 34. , to improve the correction of errors in a receiver. In the illustrated example, the transmitted data stream is multicanalized time division frames of 432 milliseconds (ms). Each frame has 10,880 bits that follow the RS coding, spiral decoding and puncturing. As illustrated by block 50 in Figure 6, the consecutive bits in one of the punctured data groups are displaced by 2720 bits since the punctured data groups 36 each consist of 5440 bits and have two groups of data of 2720 bit channel. The dispersion of the channel data group is illustrated at 60 in Figure 7 for one of the channel data groups 45. Similiarly, the interleaving is performed in the other channel data group 45 in the drilled data group, as well as for both groups of channel data in the other drilled data groups 36. With continued reference to Figure 6, other time interleaving functions 52, 54 and 56 are employed in accordance with the present invention. For example, the data groups 36 are interleaved with respect to each other, as illustrated by the second function 52 in Figure 6. The eight bits in each group 36 of punched data are displaced 2 * 1360 bits or a quarter of the frame of 10,880 bits. The sets of data groups are also interleaved with respect to each other, as illustrated by the third function 54 in Figure 6. For example, sets of two data groups having 16 bits per set can be interleaved. The sixteen dresses each set of data groups are moved 2 * 680 bits or an eighth of a frame of 10,880 bits, as shown in block 54 of Figure 6 and 64 in Figure 7. The first, second and third interleaving functions 50,52 and 54 operate in a complementary manner to reduce the undesired effects associated with small scale weakening. In particular, the first, second and third interleaving functions 50, 52 and 54 facilitate the maintenance of only one bit error within the restriction length of the Viterbi decoder in the receiver for continuous errors occurring in the bit stream, due to adverse channel conditions. Other interleaving functions over time are used, as indicated in 56, in Figure 6, for large-scale weakening. For example, symbols are scattered by a selected number of frames or frames (for example 10 frames or 54,400 bits). It will be understood that different methods and criteria may be used to extend the bits in one or more transmitted data streams and that a bit extension may vary (eg between frames). The demultonizer 48 generates two interleaved data streams, 66 and 68, from the output of the time interleaver 46. As indicated in 58 in Figure 6, mapping of the two-bit symbol can be performed in the two interleaved data streams, 66 and 68. Figure 5 shows another exemplary coding and interleaving device, in accordance with the present invention , which demulticate the output of the spiral encoder 30, by means of the demultiplexer 48 before interleaving. The two interleaving means at time 46a and 46b are synchronized with respect to each other. With reference to Figure 8, an exemplary receiver 70 is displayed to receive two or more interleaved signals that are used to transmit the same source data. The receiver 70 comprises at least two arms, 72 and 74, of receiver, to receive the signals transmitted in the respective transmission channels, 18 and 20. In the illustrative mode, the channels are from the first and second satellites. It will be understood that if a channel of a frequency is used, only one receiver arm is necessary. As shown in Figure 8, a receiver antenna 76 is provided, which is preferably wideband sufficient to receive first and second satellite channels 8 and 10 at different frequencies. A low noise amplifier (LNA) 78 amplifies the satellite signals before the signals are divided for further processing by the respective receiver arms. A splitter 79 provides the amplified signal for each receiver arm 72 and 74. One, two or more receiver arms can be used, depending on the diversity method used for the communication system.

Each arm 77 and 74 of the receiver is provided with a down converter 80 and 82 and an analog and digital converter 84 and 86, respectively. A QPSK demodulator and synchronization unit 88 and 90 is also provided on each arm, 72 and 74, of receiver. In accordance with one embodiment of the present invention, satellite signals are formed in the time-sliced multi-scan signals (TDM) that the TDM frames have. These TDM frameworks can comprise. multichannel data of a plurality of sources. In such a case, each data stream source is encoded and interleaved as described above, as is demulticanalized for transmission in multiple channels (eg via first and second satellites). TDM frames have preambles in which frame information is provided. For example, a master frame preamble (MFP) and a fast synchronization preamble (FSP) can be provided for the synchronization of TM frames. A time slot control channel (TSCC) may also be provided in the preamble which comprises information such as a frame and data counter indicating which time slots contain data and from which sources. The QPSK demodulator and the synchronization unit use the frame information to synchronize the demodulated data streams of the corresponding satellite channel to facilitate the demulting of the TDM frames. The demodulated data streams of the receiver arms 72 and 74 are extended to the multichannel 22, ie, they are loaded into the memory array 92, using the preamble to align the data of each receiver arm. The memory array 92 facilitates the combination of the currents of the two satellites in a single stream for processing by the de-interleaver 24. The multichannel 22 stores the synchronized data streams received by the receiver units 72 and 74 in corresponding consecutive records in the first and second portions of the memory array 92. The contents of the corresponding register pairs in the first and second portions of the memory array are extracted by the deinterleaver 24 and combined in a common stream of R = 3/8 bit. The recovered data streams are weighted according to a signal quality metric (for example, the average phase error measured in the QPSK demodulator and then combining using one or more of the diversity combination methods. Figure 8, the • multichannel data stream by means of the multichannel 22 and provided to the deinterleaver 24, are deinterleaved according to the functions of time interleaving, previously described in relation to Figure 6. The data stream de-interleaved they are then decoded by means of the FEC decoder module 26. This decoding module FE preferably comprises a Viterbi 96 decoder for spiral decoding.The data stream can then be subjected to Reed-Salomon decoding and layer decoding. of service, as indicated in 98 and 100. As previously noted, service interruptions can occur in systems that broadcast data, video, audio and other information that uses radio frequencies. These interruptions can prevent receivers and particularly mobile receivers from receiving broadcast services completely, or causing them to receive a signal, so degraded that the service becomes unacceptable. These interruptions are generally due to the physical blockage of the transmission paths and the weakening of multiple paths and the reflection of the transmission path.

It will be understood that the transmitted data stream can be transmitted in separate transmission channels, using different diversity techniques. For example, interleaved data streams can be multichannel code division, using wide-spectrum modulation to allow transmission in separate channels, using the same frequency. Alternatively, the signals may be transmitted with opposite polarizations (for example cross-sectional or orthogonal polarizations, such as a horizontal circular polarization horizontal / vertical or left / right) in the separated channels, using the same frequency. Two or more of the transmission channels can be transmitted at different frequencies using any modulation, analog or digital (for example, frequency division multichannelization). Additionally, the demultiplexer 48 can be omitted and the output of the interleaver 46 can be applied to a single channel. As noted previously, a digital broadcast system can use two or more transmission channels to provide tempo and / or space diversity to mitigate service interruptions due to multiple paths, physical blocks and interference in mobile broadcast receivers. Figure 9 illustrates an exemplary satellite broadcast system 1, which employs the time diversity, which comprises at least one geostationary satellite 112 for the line of sight (LOS) of the reception of the satellite signal at the receivers, indicated generally at 114. Another geostationary satellite 115 at a different orbital position, is provided for purposes of time and / or space diversity. The system 110 further comprises at least one terrestrial repeater 118 for the retransmission of satellite signals in geographic areas, where the reception of LOS is obscured by tall buildings, hills and other obstructions. The receivers 114 can be configured for dual mode operation to receive both satellite signals and terrestrial signals and to combine or select one or both of the signals as the receiver output. However, it will be understood that where the receivers are in a fixed location, it is sufficient for such receivers to operate by receiving signals from a single source and that they can reduce the cost and complexity of such receivers if they are designed for operation in a simple manner. . The satellite broadcast segment preferably includes the coding of a broadcast channel in a time-divisionized bit-stream (TDM).

The bitstream TD is modulated before transmission by means of the satellite uplink antenna. The segment the terrestrial repeater comprises a satellite downlink antenna and a receiver / demodulator to obtain a basic band TDM bit stream. The digital basic band signal is applied to a terrestrial waveform modulator and the frequency is then transferred to a carrier frequency and amplified before transmission. According to another embodiment of the present invention, a digital broadcasting system employs concatenated spiral coding and interleaved with a single bitstream. For example, the system 110 may be configured to place all interleaved bits from a source stream in a TDM stream, as opposed to sending half of the source stream bits in one transmission channel and the other half of the bits of the source current in another transmission channel. The TDM stream can then be sent via satellite or via a terrestrial transmitter. The terrestrial information transmitted is not necessarily a terrestrial repeater 118, since the source current may originate from the terrestrial transmitter, as opposed to that received by satellite and subjected to the baseband process and the frequency translation. One of the advantages of the present invention is the improved concealment of errors in receivers, during the times of blocking the broadcast signal. A blockade of signals for five consecutive frames, for example, in a time diversity system, can use a silent audio range. in contrast, the same blockage in a system performing the present invention allows the source bitstream to be recovered using audio error concealment algorithms. With reference to Figure 9, for example, the first satellite channel can be completely blocked (for example obstructed by the ground) and the second satellite channel can be momentarily blocked for a certain number of frames or frames. Following the reception and recording of the second satellite channel, the recovered data stream may merely contain simple frame interruptions, as opposed to the interruption of many frames. The interruptions of a single frame are short enough to apply audio error concealment algorithms. The operation of the audio error concealment algorithms can also be improved by reducing the frame length, thus reducing the concealment intervals. Alternatively, audio signals in the source bit stream can be divided into two half-bit rate data streams. For example, the odd and even frames may respectively carry one of the two half-bit rate audio streams. So if a frame can carry an audio channel of 64 kilobits per second, and blockage of the satellite signal occurs, then at least 32 kbps or half-bit rate audio is available during the service interruption. Although the present invention has been described with reference to one of its preferred embodiments, it will be understood that the invention is not limited to the details thereof. Various modifications and substitutions have been suggested in the above description, and others will occur to those skilled in the art. All such substitutions are intended to be within the scope of the invention, as defined in the appended claims.

Claims

CLAIMS 1. A method for interleaving a source data stream for transmission, comprising the steps of: encoding said source data stream, to generate an output data stream, using a spiral encoding scheme, with a selected code regime, said output data stream is characterized as a series of data groups, each of said data groups comprises a plurality of perforated data groups, each of these groups of punched data having a regime of reduced code with respect to said selected code regime; interleaving said data groups, according to a plurality of time interleaving functions, to disperse said bits in said data groups, within this output data stream and generate a stream of interleaved data; and transmitting said stream of data interleaved on at least one transmission channel, these time interleaving functions are selected to scatter different groups of bits in the output data stream, selected from the group consisting of said bits in one of the punctuated data groups, said bits in the adjacent data groups and said bits in selected sets of said data groups, to thereby facilitate the reconstruction of the source data stream from at least a portion of said interleaved data stream , received by means of at least one transmission channel.
2. A method, as claimed in claim 1, wherein the interleaving functions over time are selected to facilitate the reconstruction of said source data stream, from at least a portion of said interleaved data stream, followed by a continuous blocking of said at least one transmission channel.
3. A method, as claimed in claim 1, wherein each of the punctured data sets comprises subsets of said bits, in said data sets, these subsets of bits are selected so that only a minimum number of these subsets are requires to reconstruct said source data stream from this at least one transmission channel.
4. A method, as claimed in the claim 1, wherein said at least one transmission channel is transmitted via one of a satellite transmitter and a terrestrial transmitter.
5. A method, as claimed in claim 1, further comprising the step of decoding said stream of interleaved data, using said selected code rate.
6. A method, as claimed in the claim 5, wherein said decoding is performed using spiral decoding.
7. A method, as claimed in the claim 6, wherein said spiral decoding is performed using a Viterbi decoder.
8. A method, as claimed in the claim 7, wherein said time interleaving functions are selected to optimize error correction during Viterbi decoding.
9. A method, as claimed in claim 1, wherein said time interleaving functions may vary during the transmission of the interleaved data stream. or 32
10. A method for deinterleaving an interleaved data stream, transmitted over a transmission channel, comprising the steps of: receiving said interleaved data stream; synchronize said interleaved data stream; decoding said interleaved data stream, to thereby generate a decoded data stream, using spiral decoding, said interleaved data stream comprises bits from a source data stream, which has been encoded by means of a spiral encoding, to generating a plurality of data groups, each of the data groups has a plurality of perforated data groups, said data groups are interleaved by means of interleaving functions over time, selected to disperse different groups of the bits selected from the group consisting of said bits in one of the groups of punched data, said bits in groups of adjacent data, and the bits in selected sets of data groups to facilitate the reconstruction of said data. source data stream from at least a portion of the interleaved data stream, via said transmission channel, said spiral decoding reconstructs the data stream of the source using said interleaved data stream and the thus selected sequences of bits in relation to spiral coding and said interleaving functions over time.
11. An apparatus for interleaving a data stream for transmission, this apparatus comprises: a spiral encoder, for encoding said data stream, to generate an output data stream, having a selected code rate, said data stream of output is characterized as a series of data groups, each of the data groups comprises a plurality of groups of punched data, each of the groups of punched data has a reduced code rate, with respect to said selected code regime , - an interleaver, for interleaving data groups, according to a plurality of interleaving functions in time, to disperse these groups of data, within said output data stream and generate a stream of interleaved data; and a transmitter, for transmitting said data stream interleaved on a transmission channel, said interleaving functions in time are selected to scatter different groups of bits in said output data stream, which are selected from the group consisting of said bits in one of the punctuated data groups, these bits in adjacent data groups, and the bits in the selected sets of said data groups, to facilitate the reconstruction of the source data stream from at least a portion of said stream of interleaved data, received by means of a transmission channel.
12. An apparatus, as claimed in claim 11, wherein said time interleaving functions are selected to facilitate reconstruction of said source data stream, from at least a portion of said stream of data interspersed in said transmission channel. , followed by a continuous blockage of said transmission channel.
13. An apparatus, as claimed in claim 11, wherein said transmitter is provided on a satellite transmitter and a terrestrial transmitter.
14. An apparatus, as claimed in claim 11, wherein said time interleaving functions may vary during the transmission of the interleaved data stream.